EFFECT OF QUARRY DUST AND BILLET SCALE ADDITIONS ON THE PROPERTIES OF FLY ASH BRICKS

This paper reports the effect of addition of quarry dust and billet scale on the properties of fly ash bricks. Bricks were made with fly ash and cement and varying percentages of quarry dust and billet scale. All the mixtures were made to be flowable in fresh state. The bricks were then tested for strength, modulus of rupture, ultrasonic pulse velocity, initial rate of suction, water absorption, and efflorescence. The strength of bricks ranged from 0.8 MPa to 18.9 MPa, modulus of rupture ranged from 0.13 MPa to 3.7 MPa, water absorption from 15 to 32 %, and initial rate of suction between 0.27 and 2.21 kg/m(2).min. All the bricks were categorised as non-efflorescent. It is concluded that the optimum ratio of fly ash and billet scale and quarry dust and billet scale is 1:1 to get improved strength. Furthermore, it is shown that fly ash bricks incorporating 25% of quarry dust and billet scale gives reduction in the various properties observed.